Common Linux Commands Used on the Service Console

Command

Example and Explanation

cd

Change directories.

cd /home/userChange to the directory /home/user (the home directory for a user with the user name user).

cd ..Go up one level from the current directory.

cp

Copy a file.

cp oldfile newfileMake a copy of the file oldfile in the current directory. The copy is named newfile.

cp oldfile /home/userMake a copy of the file oldfile in the current directory. The copy also has the name oldfile and is in the directory /home/user.

ln

Create a link from one file or directory to another file or directory.

ln -s /bin/program prolinkCreate a soft link (shortcut) from the existing file /bin/program to prolink. The link prolink is created in the current working directory. If you enter the command prolink, you run the program /bin/program.

ls

List the files in the current directory.

ls -alList all (-a) the files in the current directory in long (-l) format.

ls *.htmlList files in the current directory that end with .html. The * is a wild-card character that represents any number of characters. The ? is a wild-card character that represents a single character.

ls /home/userList the files in the directory /home/user.

mkdir

Make a new directory.

mkdir newdirMake a new directory called newdir beneath the current directory.
mkdir /home/newdirMake a new directory called newdir beneath the /home directory.

mv

Move a file to a new directory or rename the file.

mv myfile /home/userMove the file myfile from the current directory to the directory /home/user.

mv myfile yourfileRename the file myfile. The new filename is yourfile.

pwd

Show the path to the present working directory.

tar

Tape ARchive, a command which combines many files into one for backup purposes. Below are some example commands:

tar -cvzf /local/servcons.tar.gz --exclude /proc --exclude /local --exclude /vmfs --exclude /data /

Create a gzipped tar backup file the whole Service Console.
tar -cf /local/vm-configs.tar /data

Create a tar backup file of all files in and under /data directory.
tar -xvzf /local/vm007-config.tar.gz

Extract gzipped tar backup file to current directory.
find / -type f -iname vm007* | tar -czvf /local/vm007-backup.tar.gz -
Find all files starting as 'vm007', and create a compressed backup tar file of them.

gzip|gunzip

These command compress and decompress files. The recommended and default extension is .gz.

more|less

These commands are almost the same, and usually act in a pipe. They are used for file pagination to terminal. Below are some example commands:

zcat /var/log/vmksummary.1.gz | less
more /etc/passwd

rm

Remove a file.

rm deadfileRemove the file deadfile from the current directory.

rmdir

Remove a directory.

rmdir goneRemove the directory gone, which exists beneath the current directory.

Command

Example and Explanation

cat

Concatenate the contents of files and display the content on the screen.

cat /proc/vmware/memDisplay the contents of the file/proc/vmware/mem.

find

Find files under a specified directory that match conditions you specify.

find / -name myfil*Find files in the root directory and all directories under it that have file names beginning with myfil. The * is a wild-card character that represents any number of characters. The ? is a wild-card character that represents a single character.

find -name '*.vmx' -print -exec chown User2 {} \;Find all files in this directory and all subdirectories that end with .vmx, display the names of all files that are found on the screen and, for each file (indicated by the curly braces — {}), change its owner to User2.

The -print option is not necessary, but it is handy to track the progress of the find command. If you do not use -print, the find command is silent except for error messages from find or from chown.

find -name '*.vmx' -exec grep -il 'SOMETHING' {} \;Find all files in this directory and all subdirectories that end with .vmx and look for the pattern SOMETHING in each of the files. The -i option to grep makes the search case-insensitive. The -l option to grep causes grep to display the names of the files that have SOMETHING in them. When a file is found that contains SOMETHING, this command displays the full path to the file from the current directory (for example,./virtualmachines/Linux/RedHat71Test/redhat71.vmx).

grep

Search for a specified text pattern in a specified directory or list of files and display the lines in which the pattern is found.

grep "log file" *Search all the files in the current directory for the text string log file.

less

Display the contents of a specified file one screen at a time. Use the arrow keys to move up and down through the file.

less myfileDisplay the contents of the file myfile.

grep "log file" * | lessSearch all the files in the current directory for the text string log file and use less to display the results so you can scroll up and down through them.

more

Display the contents of a specified file one screen at a time. Use the spacebar to move forward through the file a screen at a time; use the Enter key to move forward through the file one line at a time.

more myfileDisplay the contents of the file myfile.

grep "log file" * | moreSearch all the files in the current directory for the text string log file and use more to display the results so you can view them one screen at a time.

Command

Example and Explanation

apropos

Find commands with descriptions that include a specified word. Displays the name of the command and the first line of the description.

apropos fileFind commands with descriptions that include the word file.

apropos file | lessFind commands with descriptions that include the word file and use less to display the results so you can scroll up or down through them.

du

Display usage in kilobytes for contents of the current directory or for a specified file or directory.

du /binShow how much disk space is used by the /bin directory.

vdf

vdf is an ESX Server-customized version of the df command. Use vdf in place of the df command. vdf works with all the standard df options.

Displays free space for all mounted file systems. The listing also shows the total space, amount of space used and percentage of space used for each file system.

fdformat

Do a floppy disk format.

fdformat /dev/fd0Format a floppy disk in the first floppy disk drive.

groupadd

Add a new group.

groupadd newgroupAdd a group named newgroup to the system.

hostname

Display the system's host name.

ifconfig

Display the network interface configuration information for devices used by the service console.

insmod

Install a loadable module into the running kernel.

insmod parportInstall the loadable module named parport into the running kernel.

kill

Kill a specified process.
kill 3456Kill the process with a process ID of 3456.

kill -9 is the surest way to kill a process; however, use it only as a last resort since it will not save editor buffers.

lsmod

List all loaded modules.

lspci

List PCI devices available to the service console.

lspci -vList PCI devices in verbose mode.

mount

These commands manually mount CDs, floppies, local partitions, and remote directories to a selected local directory. The local (empty) directory must exist before the mount can succeed. Example mound command would be "mount /dev/sdb5 /data". Permanent mounting is done by editing the /etc/fstab file.

mount: Shows all the active mounts.
mount -a: Remounts everything specified in /etc/fstab file.
mount /dev/cdrom: This command does the default mounting of a CD to the default mount point. In Service Console the CD is mounted to /mnt/cdrom directory.
mount /mnt/floppy: Mounts a normal 1440KB floppy (/dev/fd0) to the specified directory.
mount -t iso9660 -o loop /local/w2005srv.iso /mnt/isocd: Mount a CD/DVD ISO image file to the specified directory. This is very useful for testing and other purposes. The mount point directory must exist (mkdir /mnt/isocd) before mounting.

passwd

Change your password.

passwd userChange the password for a user named user. You must be logged in as the root user (su) to change another user's password.

ps

Show names, process IDs and other information for running processes.

ps -efShow full (-f) information about every (-e) running process.

shutdown

Shut down the computer.

shutdown -h 5Completely halt (-h) the computer in 5 minutes.

shutdown -r nowShut down and restart (-r) the computer immediately.

umount

Unmount a specified device.

umount /mount/floppyUnmount the device currently mounted at /mount/floppy.

useradd

Add a new user to the system.

useradd newuserAdd a new user with a user name of newuser to the system.

who

Show the user names of all users logged in to the system.

whoami

Show what user name you are currently using on the system.

man

Prints the manual page for a command or a configuration file entered as a parameter to this command.

reboot

Does a nice reboot on the system. Does "Force Power Off" for the VMs.

halt

Does a nice halt on the system. Does "Force Power Off" for the VMs.

shutdown

Generic command for shutting down or rebooting the system.

fdisk

Command line disk partitioning program in Linux. It is powerful and has a very simple user interface.

fdisk /dev/sdb: On command line, starts fdisk against second available SCSI disk. "sda" is the first SCSI disk, "sdc" is the third SCSI disk etc. VMware ESX Server is installed on /dev/sda, and the external storage is /dev/sdb, and maybe some others too.
p: Fdisk subcommand, prints the current partition table on current disk.
d: Fdisk subcommand, deletes an existing partition. Enter the partition number to delete. It is recommended to printout the current partition table before deleting anything.
n: Fdisk subcommand, creates a new partition. Select partition type (primary, extended, or logical). Almost always you should use the default starting cylinder. For size, enter "+NNNNNm", where NNNNN is the size in megabytes.
t: Fdisk subcommand, change partition type (id). By default fdisk creates ext2 type partitions. We might also want to use id "fb", the vmfs type, or some other type.
w: Fdisk subcommand, writes the current partition table to disk. If you don't get any errors, you don't have to reboot. If you get errors at this point, the new partition table is used only after next system boot.

mke2fs

This command formats a partition for ext2, or ext3 file system.

mke2fs -j /dev/sdb1: Formats /dev/sdb1 using ext3 file system.
mke2fs /dev/sdb1: Formats /dev/sdb1 using ext2 file system

kudzu

This is the RedHat's tool to detect and configure hardware: adding new and removing old. When you run kudzu, or system runs it at bootup, be careful. Kudzu might offer to remove hardware you have dedicated solely to the VMs. Know your hardware and configuration. It might be a good idea to refer to /etc/modules.conf file before running kudzu. A safe action to select in kudzu is "Do nothing". Select it when in doubt.

With this 'disk dump' command you can create ISO images and floppy images. You can also use it to create imagefiles of partitions and whole disks. Below are some example commands:

dd if=/dev/cdrom of=/local/suse90pro-dvd1.iso bs=2048
dd if=/dev/cdrom of=/local/w2003srv.iso bs=2048: The above two examples create an ISO image of a CD/DVD. You can safely ignore the error message usually shown at the end of the media.
dd if=/dev/fd0 of=/local/bootfloppy1.img bs=1440k: This command creates a floppy image quickly.
dd if=/dev/fd0 of=/local/bootfloppy2.img bs=512: This is a bit slower version of the above example.


ntpdate

This command takes an NTP server as a parameter and synchronises the clock once. This command doesn't work when local NTP daemon is running. Example: ntpdate ntp1.funet.fi

chmod

This command is the main command for changing file modes. Like chown, it can do things recursively with parameter "-R". Below are some example commands:

chmod -R 0775 /vmfs/* /data/* c
hmod u=rwx,g=rwx,o=r /vmfs/freebsd462/*
chmod g+rwx /vmfs/vm007/*
chmod -R u+rwx,g=r,o-rwx /var/log/*
chmod u=rw,g=rw,o=r /etc/modules.conf
chmod 664 /etc/modules.conf
chmod u=rw,g=rw /vmfs/*/*.dsk

It appears, that this last example works rather nicely. Note, that those VMs which are powered-on, have their .dsk files locked.